With the progress of science and technology, the utility and popularity of the electronic product grow obviously. In some places, such as conference room, interior of car or airplane, as light is dim, an operation of keyboard is difficult when a user operates electronic products, such as a computer, PDA, projector, mobile phone, etc.
To solve the above-mentioned problem, Taiwanese Utility Model Patent Publication No. M248011 discloses a backlight button. The backlight button includes a button body and a guiding element. The button body is transparent and the guiding element is extended from at least one side of the button body. A light-emitting element is disposed in a position of a printed circuit board (PCB), which corresponds to the button body, and an inching switch is disposed in the portion of the PCB, which corresponds to the guiding element. When a user presses the button, the guiding element actuates the inching switch to turn on the light-emitting element, and the light from the light-emitting element directly projects onto the button body, and thus, the button also emits light.
However, the transparent button results in the light projecting directly into the user's eyes, which incurs the discomfort for the user. Referring to FIG. 1, another conventional design of a backlight button includes an opaque button 10, a transparent light-guiding element 11 disposed along a perimeter of the button 10, and a light-emitting element 12 disposed under the light-guiding element 11. Via a light-guiding ability of the light-guiding element 11, the perimeter of the button 10 has a ring of backlight. But the design of installing the light-emitting element 12 under the light-guiding element 11 still results in dazzling spots on a light-exiting surface of the light-guiding element 11 and light non-uniformity. To lessen the light non-uniformity, it is necessary to evenly install more light-emitting elements 12 along the perimeter of the button 10 to achieve light uniformity. However, utilizing more light-emitting elements 12 results in more fabrication cost and power consumption.